Merge pull request lammps#4542 from akohlmey/add-json-lib

Integrate header-only JSON library

Author: akohlmey

src/info.cpp

@@ -34,6 +34,7 @@
 #include "group.h"
 #include "improper.h"
 #include "input.h"
+#include "json.h"
 #include "lmpfftsettings.h"
 #include "modify.h"
 #include "neighbor.h"
@@ -291,6 +292,7 @@ void Info::command(int narg, char **arg)
     utils::print(out,"\nCompiler: {} with {}\nC++ standard: {}\n",
                platform::compiler_info(),platform::openmp_standard(),platform::cxx_standard());
     fputs(get_fmt_info().c_str(), out);
+    fputs(get_json_info().c_str(), out);
 
     fputs("\nActive compile time flags:\n\n",out);
     if (has_gzip_support()) fputs("-DLAMMPS_GZIP\n",out);
@@ -1320,6 +1322,16 @@ std::string Info::get_fmt_info()
 
 /* ---------------------------------------------------------------------- */
 
+std::string Info::get_json_info()
+{
+  return fmt::format("Embedded JSON class version: {}.{}.{}\n",
+                     NLOHMANN_JSON_VERSION_MAJOR,
+                     NLOHMANN_JSON_VERSION_MINOR,
+                     NLOHMANN_JSON_VERSION_PATCH);
+}
+
+/* ---------------------------------------------------------------------- */
+
 void Info::get_memory_info(double *meminfo)
 {
   double bytes = 0;

src/info.h

@@ -50,6 +50,7 @@ class Info : public Command {
                                       const std::string &);
   static std::string get_fft_info();
   static std::string get_fmt_info();
+  static std::string get_json_info();
   static bool has_gpu_device();
   static std::string get_gpu_device_info();
   static std::string get_accelerator_info(const std::string &pkg = "");

src/json.h

@@ -0,0 +1,25 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/, Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifndef LMP_JSON_H
+#define LMP_JSON_H
+
+// wrapper around including the JSON parsing and writing class
+// Do NOT include in any header file
+
+#include "../third_party/nlohmann/json.hpp"
+
+namespace LAMMPS_NS {
+using json = ::nlohmann_lmp::json;
+}
+#endif

src/lammps.cpp

@@ -1456,6 +1456,7 @@ void LAMMPS::print_config(FILE *fp)
              platform::compiler_info(),platform::openmp_standard(),
              platform::cxx_standard());
   fputs(Info::get_fmt_info().c_str(),fp);
+  fputs(Info::get_json_info().c_str(),fp);
 
   int major,minor;
   std::string infobuf = platform::mpi_info(major,minor);

src/main.cpp

@@ -17,6 +17,8 @@
 #include "input.h"
 #include "library.h"
 
+#include "json.h"
+
 #include <cstdlib>
 #include <mpi.h>
 #include <new>
@@ -75,6 +77,11 @@ int main(int argc, char **argv)
     finalize();
     MPI_Abort(MPI_COMM_WORLD, 1);
     exit(1);
+  } catch (json::exception &je) {
+    fprintf(stderr, "\nJSON library error %d: %s\n", je.id, je.what());
+    finalize();
+    MPI_Abort(MPI_COMM_WORLD, 1);
+    exit(1);
   } catch (std::bad_alloc &ae) {
     fprintf(stderr, "C++ memory allocation failed: %s\n", ae.what());
     finalize();

third_party/README

@@ -0,0 +1 @@
+This folder contains copies of third-party software